package main;

//HardDisk.java  
public class HardDisk {  
private int amount; // 通常这里会用更大的单位如GB, 但为了简化示例我们保持int类型  

public int getAmount() {  
   return amount;  
}  

public void setAmount(int amount) {  
   this.amount = amount;  
}  
}  